It's unfair that Republican appointees have dominated the Supreme Court for the last 50 years or so. Elsewhere I've blamed LBJ for this.
Currently liberals argue that the court is too conservative. That's true. But it's also true that the court has not always been a moderating influence, keeping America on a middle way. Back in the days of the Warren court it was fairly consistently more liberal than the country. IIRC there weren't majorities in the country supporting decisions like Brown, Carr, MIranda.
It's also worth remembering that people on the right were talking about "Impeach Warren". So far the liberals today aren't talking about impeachment.